Hydration backpack



FIG. 1 is a front perspective view of a hydration backpack showing my new design;

FIG. 2 is a front plan view thereof;

FIG. 3 is a back plan view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof; and,

FIG. 7 is a right side elevational view thereof.

The broken lines showing of elements on the hydration backpack illustrate stitching and form no part of the claimed design. 

CLAIM The ornamental design for a hydration backpack, as shown and described. 